The Garbage-Can Illusion as a Teaching Demonstration

Abstract

The height but not the width of a classroom garbage can was overestimated by 27 of 31 introductory psychology students. The average estimate was nearly 50% larger than the actual height of the garbage can. We argue that demonstrations that emphasize the ecological validity of laboratory conceptualizations of illusions can help to stimulate student interest in and understanding of perception. © 1997, SAGE Publications. All rights reserved.